2.7 Review (Replication - PCR)

Helicase breaks the following bonds between nitrogenous bases:

• Hydrogen bonds
• Covalent bonds
• Phosphodiester bonds
• Ionic bonds

The direction of DNA synthesis:

• 5' to 3'
• 3' to 5'
• Depends on which strand is being replicated
• One Direction

In a semi-conservative model of DNA replication, which of the following is true?

• The daughter DNA molecule consists of 1 parent strand and 1 new strand
• The daughter DNA molecule consists of 2 parent strands
• The daughter DNA molecule consists of 2 newly formed strands
• The daughter DNA molecule consists of an uneven mix of old and new strands

Which of the following is the first step in PCR?

• DNA is heated to separate the strands
• DNA is cooled to allow primers to anneal
• Taq polymerase elongates the new strands
• Nucleotides bonds to their complementary base pairs

Which of the following is the second step in PCR?

• DNA is heated to separate the strands
• DNA is cooled to allow primers to anneal
• Taq polymerase elongates the new strands
• Nucleotides bonds to their complementary base pairs

Which of the following is the third step in PCR?

• DNA is heated to separate the strands
• DNA is cooled to allow primers to anneal
• Taq polymerase elongates the new strands
• The double helix reforms

Why are DNA primers added to the PCR process?

• DNA polymerase III cannot start elongating a new strand from scratch
• Helicase cannot unwind the DNA molecule without them
• The DNA molecule will denature without them
• They are there to speed up the process

Which scientists provided evidence for the model of semi-conservative DNA replication?

• Meselson and Stahl
• Watson and Crick
• Wilkins and Franklin
• Hershey and Chase

In the M&S experiment, how many bands showed up on the photographic film after the first generation?

• 1 representing the hybrid ¹⁵N/¹⁴N DNA
• 1 representing the ¹⁵N DNA and 1 representing the ¹⁴N DNA
• 1 band that represented only ¹⁴N DNA
• 1 band that represented the ¹⁵N DNA and 1 band representing the hybrid DNA

Which of the following statements about DNA replication is TRUE?

• the leading strand is replicated continuously, while the lagging strand is replicated discontinuously
• the leading strand is replicated discontinuously, while the lagging strand is replicated continuously
• both the leading and lagging strands are replicated continuously
• both the leading and lagging strands are replicated discontinuously